This application proposes a mentored training program to develop Travis Lovejoy, PhD, MPH into an independent VA Health Services Research & Development (HSR&D) investigator with expertise in the treatment and study of pain in specialty substance use disorder (SUD) treatment settings. Dr. Lovejoy is a Clinical Psychologist and junior Health Services Researcher at the Portland VA Medical Center and Assistant Professor of Psychiatry at Oregon Health & Science University (OHSU). Dr. Lovejoy's training objectives for the Career Development Award (CDA) include (a) establishing further content expertise in pain and substance use disorders, (b) developing proficiency in the use of VA administrative data to answer key research questions, and (c) enhancing competency in qualitative and mixed methods approaches as they apply to clinical trials and implementation science. His training plan consists of formal coursework, advanced training workshops, and mentor-guided study. Dr. Lovejoy is supported by an accomplished mentoring team of health services researchers that includes Steven Dobscha, MD, Director of the Center to Improve Veteran Involvement in Care (CIVIC), the newly funded VA HSR&D Center of Innovation at Portland VA Medical Center; Linda Ganzini, MD, MPH, Associate Director of CIVIC and Professor of Psychiatry and Medicine at OHSU; Benjamin Morasco, PhD, CIVIC Research Investigator and Associate Professor of Psychiatry at OHSU; Dennis McCarty, PhD, Professor and Vice Chair of Public Health and Preventive Medicine at OHSU; and Hildi Hagedorn, PhD, Core Research Investigator at the Minneapolis VA Medical Center and Implementation Research Coordinator for the SUD Quality Enhancement Research Initiative (SUD QUERI). The resources at OHSU and the Portland VA Medical Center support the transition of junior researchers from mentored study to research independence. These resources, combined with the expert guidance of the mentoring team, will provide the ideal opportunity for Dr. Lovejoy to develop into an independent VA HSR&D investigator. Dr. Lovejoy will complete three interrelated studies during the CDA. Study 1 will use VA administrative data to characterize pain treatment utilization in a national sample of Veterans following initiation of specialty SUD treatment and compare pain treatment utilization to that of Veterans with co-occurring chronic pain and SUDs who do not initiate specialty SUD care. Findings from this study will inform a VA HSR&D Investigator Initiated Research proposal for a mixed methods study that will evaluate practices of high-and low- performing VA SUD treatment programs in managing Veterans' chronic pain. Study 2 will qualitatively examine pain treatment experiences and preferences in Veterans with chronic pain currently receiving specialty SUD treatment at a single VA Medical Center. Additional qualitative focus groups and interviews with key VA Medical Center stakeholders will examine barriers and facilitators to implementation of a collaborative pain intervention into a specialty SUD treatment setting. Data from study 2 will inform tailoring of an evidence- based, primary care-delivered collaborative pain intervention for implementation in a specialty outpatient SUD treatment setting. Study 3 is a pilot non-controlled trial of the tailored collaborative pain intervention delivered in the specialty SUD treatment setting. Findings from this pilot trial will inform a second VA HSR&D Investigator Initiated Research proposal for a multi-site effectiveness trial of the collaborative pain intervention that concurrently evaluates intervention implementation. Successful completion of the proposed research and training will prepare Dr. Lovejoy to become an independent VA HSR&D investigator with expertise in pain and substance use, clinical trials, and mixed methods research.